I have an '08 Nytro with Powderlites Stage 2 kit on it, purchased this last fall from a prior owner that maybe didn't disclose his true reason for selling. The install is very clean, the kit is well thought out and the whole sled is immaculate, but I have had constant problems trying to get it to run WOT without sputter (feels like lean-down). It is most peculiar--it will run crisp on throttle response and between 11-12.5 on A/F ratio up to about 65% throttle, beyond that it falls on its face and sputters and the A/F gauge goes to 13-15 or sometimes blanks out "--" and I hurry and get off the throttle. It will run up to 65% throttle at 15 psi boost and run 100 mph on flat and 75+ up a big hill, but I can't go WOT or it sputters. It does this at min 10psi boost and at max 15 psi boost regardless. I ride at 6-10K feet elevation and it does it regardless of elevation. I have suspected the following and tested accordingly (results show no problem):
1) Wrong Map (I have tried Powderlites maps posted Last Feb, 2010, April 2010, and the more recent Nov 26, 2010 map that Dave posted. I have even created my own map loading up to 150% duty cycle top to bottom in the final three columns of the map and it still seems to lean out and sputter on top. I have confirmed that the changes take, because I can sit and run it on the laptop and add enough/take away enough fuel in first column to get the motor to die)
2) RB3 Connection (I pulled it and confirmed that it was loaded with dielectic grease; i put more in, but don't see this as a problem)
3) RB3 Firmware (Dave emailed me the latest firmware RB3_Nytro_3Bar-V47)
4) RB3 Configuration (I have become confident in the purpose of every parameter in RB3 Configuration: Correction Pump Settings (I like it best at 2%/35%/200ms for throttle response), Voltage Max/Min settings (currently at 1.75/4.71), RPM limiter settings (+500 rpm), Switch Map settings, Hold RPM settings, etc... I have even hand-pump tested the 2-bar MAP sensor AND the load % readout in Rapid Master and now have a precise conversion table showing manifold gauge boost to MAP voltage to RB3 load% comparison to assist with fine tuning of voltage parameters to identify fuel map column per gauge boost read out. I have confirmed that all of these parameters work as they are supposed to, with the exception of Correction Pump adjustment off idle since it is was designed to be driven off of throttle position and in the Powderlites configuration it is driven off of MAP sensor voltage which actually drops temporarily when you open the throttle due to manifold vacuum)
5) Fuel filter (I pulled the tank and had some particles lodged in the fuel filter. After cleaning I noticed no differences)
6) Fuel hoses ( I have hand traced fuel hose from tank to pump, to fuel rail and to fuel regulator. Slightly steep bend in one place, but looks good)
7) Fuel (I started out running pump gas but feared for the life of my engine with A/F spikes way above 13 at WOT. I went to Avgas (ran best) and now VP 110. Will go back to pump gas once lean-down is solved)
8) Onboard Diagnostics (I have no fault codes and I have went through every diagnostic check available on the multifunction display. Everything checks out okay)
9) Fuel Pump (I questioned output so I adjusted regulator up to max pressure and fuel pump can hold over 100psi. I ran bypass into a handheld gas can and output was phenomenal)
10) Fuel Regulator (My regulator is a large, flat red anodized unit with a 13mm hex nut and an allen head set screw for regulation adjustment. It bypasses to the fuel tank and has an airline tied into it from the top of the airbox. There is no name on it so I don't know the brand. I bench tested it and presume that it is a 2:1 rising rate regulator. Setting it at 50 psi at atmosphere results in about 75 with 10 psi above atmosphere plumbed in. My sled has vent cut-outs above and below the fuel pressure regulator so it stays cool so I don't expect vapor lock)
11) Spark Plugs (Steve Packer ("TurboDoc") rode my sled while I rode his Aerocharged Pro RMK and he suggested I change the plugs. I pulled the originals and replaced with NGK iridiums of same heat range. I noticed very little/no difference)
12) Boost Leakage (My motor shuts down if I hold my hand over muffler outlet so I don't suspect any exhaust problems. I have hand traced the whole intake plumbing and I don't have problems making boost so I don't suspect anything here)
13) Clutching (I have a shockwave adjustable helix so it is easy to keep off the rev limiter so I don't suspect this is a problem)
As you can see, all of the more obvious stuff checks out fine. I went up tonight to do some very detailed tests, even holding the laptop while riding across a field and viewing Rapid Master read-outs. I ran through every map and voltage configuration that Dave has published on this site and I ran the full scale of available boost (per bleed off valve controller) and got great results from idle to 65-70% throttle. Opening it up that last little crack just cuts it off immediately every time and it cleans up when I cut back throttle. Tonight I observed the most interesting thing yet--I could hold 70% throttle and run 85 mph across field at 8800 rpm shift out and when I gave it more throttle, the rpms would drop off to 8500-8600 and motor would cut out like out of fuel.
My final thought tonight was that the stock TPS sensor might be screwed up. I have not done a voltage readout, but under Diagnostics mode, it ranges from 16% to 96%, which is within factory tolerance.
Any help on what to check next would be greatly appreciated.
2008 Nytro MTX
Powderlites Stage 2 Turbo
KMOD Skid
1) Wrong Map (I have tried Powderlites maps posted Last Feb, 2010, April 2010, and the more recent Nov 26, 2010 map that Dave posted. I have even created my own map loading up to 150% duty cycle top to bottom in the final three columns of the map and it still seems to lean out and sputter on top. I have confirmed that the changes take, because I can sit and run it on the laptop and add enough/take away enough fuel in first column to get the motor to die)
2) RB3 Connection (I pulled it and confirmed that it was loaded with dielectic grease; i put more in, but don't see this as a problem)
3) RB3 Firmware (Dave emailed me the latest firmware RB3_Nytro_3Bar-V47)
4) RB3 Configuration (I have become confident in the purpose of every parameter in RB3 Configuration: Correction Pump Settings (I like it best at 2%/35%/200ms for throttle response), Voltage Max/Min settings (currently at 1.75/4.71), RPM limiter settings (+500 rpm), Switch Map settings, Hold RPM settings, etc... I have even hand-pump tested the 2-bar MAP sensor AND the load % readout in Rapid Master and now have a precise conversion table showing manifold gauge boost to MAP voltage to RB3 load% comparison to assist with fine tuning of voltage parameters to identify fuel map column per gauge boost read out. I have confirmed that all of these parameters work as they are supposed to, with the exception of Correction Pump adjustment off idle since it is was designed to be driven off of throttle position and in the Powderlites configuration it is driven off of MAP sensor voltage which actually drops temporarily when you open the throttle due to manifold vacuum)
5) Fuel filter (I pulled the tank and had some particles lodged in the fuel filter. After cleaning I noticed no differences)
6) Fuel hoses ( I have hand traced fuel hose from tank to pump, to fuel rail and to fuel regulator. Slightly steep bend in one place, but looks good)
7) Fuel (I started out running pump gas but feared for the life of my engine with A/F spikes way above 13 at WOT. I went to Avgas (ran best) and now VP 110. Will go back to pump gas once lean-down is solved)
8) Onboard Diagnostics (I have no fault codes and I have went through every diagnostic check available on the multifunction display. Everything checks out okay)
9) Fuel Pump (I questioned output so I adjusted regulator up to max pressure and fuel pump can hold over 100psi. I ran bypass into a handheld gas can and output was phenomenal)
10) Fuel Regulator (My regulator is a large, flat red anodized unit with a 13mm hex nut and an allen head set screw for regulation adjustment. It bypasses to the fuel tank and has an airline tied into it from the top of the airbox. There is no name on it so I don't know the brand. I bench tested it and presume that it is a 2:1 rising rate regulator. Setting it at 50 psi at atmosphere results in about 75 with 10 psi above atmosphere plumbed in. My sled has vent cut-outs above and below the fuel pressure regulator so it stays cool so I don't expect vapor lock)
11) Spark Plugs (Steve Packer ("TurboDoc") rode my sled while I rode his Aerocharged Pro RMK and he suggested I change the plugs. I pulled the originals and replaced with NGK iridiums of same heat range. I noticed very little/no difference)
12) Boost Leakage (My motor shuts down if I hold my hand over muffler outlet so I don't suspect any exhaust problems. I have hand traced the whole intake plumbing and I don't have problems making boost so I don't suspect anything here)
13) Clutching (I have a shockwave adjustable helix so it is easy to keep off the rev limiter so I don't suspect this is a problem)
As you can see, all of the more obvious stuff checks out fine. I went up tonight to do some very detailed tests, even holding the laptop while riding across a field and viewing Rapid Master read-outs. I ran through every map and voltage configuration that Dave has published on this site and I ran the full scale of available boost (per bleed off valve controller) and got great results from idle to 65-70% throttle. Opening it up that last little crack just cuts it off immediately every time and it cleans up when I cut back throttle. Tonight I observed the most interesting thing yet--I could hold 70% throttle and run 85 mph across field at 8800 rpm shift out and when I gave it more throttle, the rpms would drop off to 8500-8600 and motor would cut out like out of fuel.
My final thought tonight was that the stock TPS sensor might be screwed up. I have not done a voltage readout, but under Diagnostics mode, it ranges from 16% to 96%, which is within factory tolerance.
Any help on what to check next would be greatly appreciated.
2008 Nytro MTX
Powderlites Stage 2 Turbo
KMOD Skid
